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Dinopedia:Tyrannosaurus rex
Tyrannosaurus rex (ty-RAN-o-sawr-us) meaning "tyrant lizard king" (Greek tyrannos = tyrant + sauros = lizard + rex = king), also known colloquially as T. rex, 'it was a giant carnivorous theropod dinosaur from the Upper Maastrichtian, the last stage of the Cretaceous Period, 68–65 million years ago. Its fossil remains are relatively rare, as of 2008 only 31 specimens had been found, including three complete skulls. Some ''Tyrannosauruses could grow 40-50 (12-15 m) feet long, reach heights of 16-21 (5-6.4 m) feet tall, and weigh between 7-10 tons (14,000-20,000 lbs), meaning this dinosaur could grow as big as Giganotosaurus or Carcharodontosaurus (some of the largest predatory land animals of all time) and larger than an African bull elephant. What's more is like other reptiles, T. rex continued to grow as long as it lived, meaning we could maybe find even bigger tyrannosaurs in the future. The first specimens found played an important role in the Bone Wars. It lived throughout what is now western North America, with a much wider range than other tyrannosaurids. It was among the last non-avian dinosaurs to exist prior to the Cretaceous–Tertiary extinction event. While Tyrannosaurus ''and its relatives ruled the north, abelisaurs such as ''Carnotaurus ''ruled the south. ''Tyrannosaurus rex is probably the most well-known dinosaur, ranging from toys to television shows. It is celebrated as the "King of the Dinosaurs", however, there may have been some carnivorous dinosaurus that were bigger. In 1892, Edward Cope described the first known Tyrannosaurus rex skeleton as Manospondylus gigas, but this is now considered a Nomen oblitum. Barnum Brown's 1900 discovery of "Dynamosaurus imperiosus," now called Tyrannosaurus rex, ''Tyrannosaurus type species. He found two more specimens, in 1902 and 1905. ''Tarbosaurus'' was at one point considered a second Asian species of Tyrannosaurus, but was later reclassified as either Tarbosaurus bataar ''or ''Tyrannosaurus bataar. But Tyrannosaurus rex may not be not the biggest carnivorous dinosaur. Spinosaurus may be the biggest carnivorous dinosaur ever discovered with the largest estimates being 55 feet (17 m) long. Giganotosaurus may have been right behind Spinosaurus, ''and Carcharodontosaurus is right behind ''Giganotosaurus. In Jurassic Park 3, a sub-adult Tyrannosaurus fought a Spinosaurus and lost, but this battle was unrealistic. Recent studies now show that Spinosaurus was less powerful and designed more for catching fish and hunting small dinosaurs. The T. rex's initial bite at the beginning of the fight should have killed the Spinosaurus since it's got a bone-crushing bite, but even if it didn't, the Spinosaurus would've died later from infection. However, there is no complete skeleton of Spinosaurus, and Carcharodontosaurus and Giganotosaurus are rather close to T. rex in size, so the placement for biggest carnivorous land animal is currently too close to call. Skin and feathers In 2004, the scientific journal Nature published a report describing an early tyrannosauroid, Dilong paradoxus, from the famous Yixian Formation of China. As with many other theropods discovered in the Yixian, the fossil skeleton was preserved with a coat of filamentous structures which are commonly recognized as the precursors of feathers. It has also been proposed that Tyrannosaurus and other closely related tyrannosaurids had such protofeathers. However, skin impressions from large tyrannosaurid specimens show mosaic scales.While it is possible that protofeathers existed on parts of the body which have not been preserved, a lack of insulatory body covering is consistent with modern multi-ton mammals such as elephants, hippopotamus, and most species of rhinoceros. As an object increases in size, its ability to retain heat increases due to its decreasing surface area-to-volume ratio. Therefore, as large animals evolve in or disperse into warm climates, a coat of fur or feathers loses its selective advantage for thermal insulation and can instead become a disadvantage, as the insulation traps excess heat inside the body, possibly overheating the animal. Protofeathers may also have been secondarily lost during the evolution of large tyrannosaurids like Tyrannosaurus, especially in warm Cretaceous climates. If anything, the feathers would've been used to show off during courtship to attract mates in large tyrannosaurs. Even though the larger adult tyrannosaurs probably didn't have feathers, the babies, which were much smaller and needed more warmth than the adults, probably hatched with feathers and lost them as they grew. Killer Instinct There has been ongoing debate as to how Tyrannosaurus found its food. Most people believe it was a predator, hunting down and killing its food in the same way lions do. However, some believe it was a scavenger, as evidenced by its large olfactory bulbs (which indicate a phenomenal sense of smell). The best possible conclusion is that Tyrannosaurus was both a predator and a scavenger, depending on what happened around the Tyrannosaurus. The reason for this conclusion is that it's huge size makes it hungry most of the time. For example, if a Tyrannosaurus ran into a Triceratops carcass, It would eat it because it is easier when you don't have to work for your food. As big and powerful as T. rex ''was, a lone one probably wouldn't go after a ''Triceratops unless it was injured, young, old, sick, or if the tyrannosaur was starving or fit and big enough to, like most predators today. Evidence has shown that Tyrannosaurus was also cannibalistic when the sitiuation demanded it, or after killing it for mating or territory. When Tyrannosaurus rex did hunt, its strategy when it was alone was to ambush its prey and either head-butt it or take a large bite out of its flesh and wait until the prey item weakens from infection or bloodloss. When it was in pairs, it was to attack from both sides and gang up on the prey. If it hunted in family groups, the juveniles would chase to the direction of the adults, where they would kill it. Studies now show that tyrannosaurs in the North hunted ceratopsians like Triceratops, ankylosaurs like Ankylosaurus, and hadrosaurs like Edmontosaurus, while ones in the South would hunt both of those prey items plus sauropods like Alamosaurus. The concept that makes Tyrannosaurus so deadly is that it had a big head (up to 5 ft long) and great jaws that could dislocate like a snake to swallow large pieces of meat. It also banana-sized teeth (3-14 in.) and could bite 600 lbs. (270 kg) of meat at a time and swallow it whole, sometimes breaking the teeth off when biting but growing them back repeatedly. Unlike most predators, T. rex would also eat basically the whole carcass, bones and all. The teeth made Tyrannosaurus different from most predators, because these teeth were blunter and stronger and more suited to crush bone and penetrate armor instead of slice through flesh. The average bite force of Tyrannosaurus astounded scientists when they used calculations from crocodile bite forces to find out that Tyrannosaurus had a bite force of 3 tons (6,000 lbs) to 10 tons (20,000 lbs) per square inch. This tremendous amount of force is enough to bite through a steel oil drum. One theory is that Tyrannosaurus had a mouth full of deadly bacteria other than its bone-crushing pair of jaws which helped its kill prey, meaning it could use those deadly teeth in two ways. This could have been possible if you consider the predatory theory. Tyrannosaurs could probably use hunting tactics which required lunging at prey from short distances and then crushing them with its jaws. It also could break bones with it's tail, teeth and claws, and could ram into prey with its rock-hard head. T. rex ''was a monstrously powerful animal, much stronger than any other carnivorous dinosaur or anything alive today. Even its tiny arms (being only three-feet long and only having two fingers) were strong, being able to lift 500 lbs. (225 kg.) with each arm! Scientists say that because of the strength of its arms, ''T. rex could use them to help lift itself off the ground or stabilize prey along with its feet. Closer bone analysis shows that where muscle tendons attatched to the bones were very large, bigger than any other muscle mass for any other animal. Also, many Tyrannosaurus skeletons show a very hard lifestyle, with healed wounds from Triceratops horns, broken legs and ribs from Ankylosaurus and other prey items, and even bite tooth puncture marks from other tyrannosaurs, probably from fighting over food, mates, or territory. However, most of the wounds on the skeletons show signs of healing, meaning T. rex could take a lot of damage and still recover. Tyrannosaurus' speed has been a topic of discussion for a while. The scavenger-approving scientists believe that T. rex couldn't run any faster than 10 mph, not even being able to outrun a human. They say it was far too large to be able to run very fast and instead had to depend on the remains of carcasses to feed itself. However, recent studies seem to debunk that theory, and hunting-approving scientists agree that T. rex had very strong, thick legs with hollow bones like birds that were longer and more muscular than any other large theropod. Another piece of evidence that T. rex may have been fast was that it had ostirich-like legs, with a tibia and femur about the same length and hollow bones, making it relatively fast. They also claim T. rex had 15-foot strides and could run up to 25 mph, despite its heavy bulk. That would make it faster than Olympic sprinters! Even if it wasn't that fast, studies seem to show that T. rex was faster than any of its prey items. This discussion along with the hunter/scavenger theory has been a long debated argument. It also seems as though if T. rex was a predator, than it held its prey down with one of its feet, using the other one and its long tail for balance, and then taking a bite out if its prey. T. rex also had specialized pads on the soles of its feet like elephants today to feel low frequencies in the ground to find and locate its prey like ceratopsians or ankylosaurs. Another terrifying aspect about Tyrannosaurus rex was the size of its brain. It was the smartest of the large theropods, and its brain was about the size of a gorilla's. Recent studies show that T. rex was probably about as smart as a lion, meaning this dinosaur could use strategic thinking to take down tough prey like Triceratops and Ankylosaurus. T. rex ''probably became so smart because unlike other large theropods, which hunted large, small-brained sauropods, it hunted tough animals that were about the same size, like ''Triceratops, so it would need to come up with a plan to kill it. That can also explain why the teeth were so much broader, thicker, and stronger than other carnivores, since there was more armor that needed to be bitten through. This brain size may also have led T. rex ''to be able to form a family pack, letting the juveniles chase after the prey items into the jaws of the adults, like lions do today. Hunting in packs or pairs could also be a factor in being able to take down tough prey. The large brain also helped ''T. rex take better care of its young, so the next generation of killers had a greater chance of surviving. The skull of T. rex also shows that it had large eyes that faced forward, giving it three-dimensional binocular vision, while most theropods had eyes that were on the sides of their heads. Taxonomy For a long time T. rex was considered part of the carnosaur genus, like Allosaurus, but a closer analysis a few years ago showed that it was actually part of its own genus; the tyranosaurids. While'' Tyrannosaurus was by far the biggest tyrannosaurid, it wasn't the only one. It had numerous relatives; [[Daspletosaurus|''Daspletosaurus]], ''Albertosaurus'', and ''Tarbosaurus'' are all part of the tyrannosaur family. The earliest known tyrannosaurs were actually small hunters. Of all it's relatives, ''Daspletosaurus'' is believed to be the direct ancestor of T. rex, ''due to its very similar appearance. The skull of a small tyrannosaur, ''Nanotyrannus, found in South Dakota, was later proved to be from an adolescent T. rex. Although Tyrannosaurus was the peak of tyrannosaur and carnivourous dinosaur evolution, it was an evolutionary dead end, with its closest descendants being birds, because of th K-T Extinction caused by a massive asteroid. Of the 31 specimens found, the most famous, most complete, and largest T. rex on display is Sue, a 42-foot (12.8 m) long Tyrannosaurus found in the badlands of South Dakota in 1990 by Susan Hendrickson. Sue's the most complete skeleton of any tyrannosaur, and was auctioned off in Washington D.C. for over $8 million. The skeleton is now on display in the Field Museum in Chicago, Illinois for everyone to see, but its skull is on a seperate case because it was too heavy to put on the actual skeleton, so they made a lighter replica and put it on the frame instead. Sue was named after the paleontologist who found it, but scientists aren't quite sure what its gender is. Not only is Sue the most complete and largest displayed T. rex, but it's also the oldest, dying at the age of 32. This seems to suggest tyrannosaurs grew continuously as they aged. Sue has given the most information of any T. rex skeleton yet, and is one of only a few Tyrannosaurus with a complete skull and forelimb. Some other famous T. rex specimens are Stan, Thomas, Samson, and Jane. Trivia *Paleontologist James Farlow calculated the number of lawyers a grown Tyrannosaurus had to eat (based on a scene from the movie Jurassic Park, in which a lawyer became T. rex fodder) to stay alive. Taken an average weight of 68 kilograms, 292 lawyers would be needed to keep one T. rex happy for a year! Popular Culture Tyrannosaurus is probably the most famous of dinosaurs. It shown in many recent movies involving dinosaurs. Its first appearance in the moves was in the 1925 film The Lost World, ''where it battles an ''Agathaumas. It also played an important role in the movie Jurassic Park ''where it killed a lawyer and two ''Deinonychus. It also appeared in the movies sequel The Lost World: Jurassic Park. ''In this movie it rampaged through San Diego in an attempt to find its offspring. It later appeared in the third sequel ''Jurassic Park 3. Here a sub-adult male Tyrannosaurus killed a Parasaurolophus and battled and was killed by a sub-adult Spinosaurus. It also starred in an episode of reknown documentary series Walking With Dinosaurs. It also appeared in several episodes of the well known documentary Jurassic Fight Club and Clash of the Dinosaurs. Another documentary it's been in is Dinosaur Revolution, ''where it showed how a family of tyrannosaurs lived until the K-T Extinction. A ''Tyrannosaurus named Heart serves as the main protaganist of the 2010 anime film You Are Umasou. Gallery Trexprofile.jpg|A Tyrannosaurus profile. Tyrannosaurus rex.jpg|Tyrannosaurus standing in a pond. Tyrannosaurus_3D_Model.jpg|3D model of Tyrannosaurus. Tyrannosaurus rex.gif Tyrannosaurus vs Spinosaurus.jpg|Tyrannosaurus vs. Spinosaurus images.jpeg T-Rex Through Wall.jpg|T-Rex Through Wall Jurassic Park T.Rex.jpg JFC Rex.jpg|T-Rex attacks Nanotyrannus ep4-trex-01.jpg|Jack Palance from Dinosaur Revolution tyrannosaurus-rex.jpg JPT.Rex.jpg|JP T.Rex in Main Hall ﻿ Category:Theropods Category:Tyrannosaurids Category:Dinosaurs of North America Category:Primeval Category:Zoo Tycoon Dinosaur Digs Creatures Category:Large Carnivores Category:Saurischians Category:Saurischia Category:Tyrannosaurs Category:Apex predators